Apparatus for manufacture of tubetype radiators



Dec. 11, 1962 A. l. RONBECK 3,067,994

APPARATUS FOR MANUFACTURE OF TUBE-TYPE RADIATORS Filed Sept. 2, 1959 2 Sheets-Sheet 1 INVENTOR. Arne I T'n beck APPARATUS FOR MANUFACTURE OF TUBE-TYPE RADIATORS 2 Sheets-Sheet 2 Filed Sept. 2, 1959 R. m ,n m a F 2 M. 7 3 d y m F 7 m A 5 OJ 0 X V 8 8 E MWM .0 .H. T v M X H X. 2i i p J J T a a R 5d 0 w w rates The present invention relates to a fixture for assembling radiator elements and more particularly for assembling radiators of the fin and tube type, such as those commonly used in the automotive and refrigeration fields.

Radiators of the fin and tube type normally comprise a series of parallel thin-wall tubes made of a metal having a high degree of thermal conductivity, such as brass or copper, and supported in a stack of closely spaced parallel cooling fins also of a metal having a high thermal conductivity. Passage of cool air through such a core structure is an effective means of cooling a liquid or gas circulating in the tubes. In automotive uses, cores of this type are normally operated with the tubes in parallel; that is, the fluid to be cooled travels through all of the tubes in the same direction. In the refrigeration field, the tubes are usually serially connected so that fluid passes sequentially through one tube after the other. In radiators of this type, the tubes may be arranged in a common plane or in parallel planes and arenormally soldered to the fins to maintain a high degree of thermal coupling between them.

The starting material for the tubes is usually brass sheet bands 0.15 mm. thick, which are formed into flat, folded tubes in a tube rolling mill, and are cut to suitable lengths for being mounted in the stack of fins.

The starting material for the fins is usually copper sheet bands 0.10 mm. thick and particularly hard-rolled. The manufacture of the fins is usually completely automated. The edges of the band are first doubled over in an edge rolling mill in order to make them stiff and to prevent them from causing injuries by cutting. The bands are then punched to provide them with holes for the water tubes, and the edges of the holes are provided with collars to increase the surface of contact with the tubes. Finally, the fins are cut to suitable lengths. If the fins are provided with two or more rows of holes for tubes in different planes, a longitudinal corrugation is made in the fin sheet between the rows of holes in order to make the fins more firm.

In assembling the tubes with the fins to form the radi ator, a fixture is used. This consists of two plates which are kept spaced from each other by suitable means so that those surfaces of the plates which face each other are parallel. These surfaces are provided with parallel grooves for receiving the fins so that the latter, when fitted in the grooves, will get support and guidance at their edges from the grooves and will take the relative positions they are intended to have in the finished radiator.

The fins are inserted by hand, individually or many at a time, into these grooves so that the holes in one fin will be aligned with the holes in another fin and permit insertion of the tubes into the holes throughout the pack of fins. The tubes are inserted by hand, one by one. When all the tubes have been inserted, the tube-and-fin radiator is withdrawn from the fixture for further treatment.

One difiiculty in thus assembling such radiators, especially when the tubes are to lie in two or more planes, is that the fins, when the tubes are passed through the holes, are supported by the fixture only at the outer edges of the fins, whereby the thin fins will be liable to bending and deformation or offer resistance in some other 'ice sembling work. In grave cases of bending of the fins, it may happen that the fins leave their grooves and slip into the adjacent grooves, the result being that the whole tubeand-fin radiator is discarded. The tubes must therefore be inserted with great care and, at most, one at a time.

An object of the invention is to overcome this difficulty and provide a fixture which supports the fins at such points that they allow a fast and rough insertion of one or more tubes at a time without any risk of the fins bending in any appreciable degree or being deformed or leaving their predetermined positions in the fixture.

Another difiiculty, which is a consequence of the liability of the fins to bend and of the lack of adequate supporting points for the fins in the ordinary fixture, is that the holes for the tubes in the fins must be made with a sufiiciently loose fit around the tubes to allow insertion of the tubes, which means unsatisfactory contact between the fins and tubes. This results in a great consumption of solder during the subsequent soldering of the tubeand-fin radiator, to provide a good joint and good heattransmission between the fins nad tubes.

Another object of the invention is to overcome the last-mentioned difficulty and to make it possible to use a tighter fit between the fins and tubes and thus permit a lower consumption of solder.

In using the prior fixtures for assembling the tubes and the fins, it has been necessary to introduce the tubes at various points in the fixture until all the tubes have been inserted, which is an inconvenience.

A further object of the invention is to remove this inconvenience and to provide such a fixture for the fins that it will be possible to introduce the tubes at one and the same point of the fixture, either by hand or by machine. This object is accomplished by an arrangement enabling the fins to be displaced stepwise in the fixture a distance corresponding to the distance between the holes in the fins each time an introduction of one or more tubes has taken place.

A fixture made according to the invention comprises a series of parallel guide plates securely connected to each other in spaced relation and provided with supporting means for fins to be fitted between the guide plates, these plates being provided at one end with re cesses which are open toward this end for receiving the tubes. Other features and advantages of the invention will appear from a preferred embodiment as described more in detail below and illustrated in the drawings, in which FIG. 1 is a perspective view of my novel fixture showing the location of the fins with three tubes inserted therein;

FIG. 2 illustrates in perspective the shape and position of the top and bottom frame members shown in FIG. 1;

FIGS. 3 and 4 are face views of one of the side frame members and one of the fin spacer plate members, respectively;

FIGS. 5 and 6 are face views of upper and lower separator members, respectively, for the fin spacer plates;

FIG. 7 is a magnified cross-sectional view of the fixture taken along line VV between points A and A of FIG. 4, showing the location of one fin in position between separators and showing how deformation is prevented as a tube is inserted in the core;

FIG. 8 is a plan view of a section of fin material;

FIGS. 9 and 10 are cross-sectional views of the fin of FIG. 8 taken along lines IX-IX and X-X, respectively, in FIG. 8; and

FIG. 11 is a cross-sectional view of a typical tube to illustrate the shape thereof.

The radiator fins, as shown in FIGS. 8, 9 and 10, are fabricated from strip stock whose edges 26 and 2.7 have been folded double in an edge rolling mill to stiffen the material and to dull the razor-sharp edges to reduce the cutting hazard encountered during handling. Longitudinal grooves 28 are embossed in the strip material either in the same rolling mill or by subsequent operation. The next phase inthe formation of the fins is that of punching the openings 13 for the tubes. This is accomplished by a piercing operation so that the unwanted material will be pushed through the opening and leave flaps or collars as shown at 29, 30 and 31 in FIG. 9. These projecting collars function as stiifeners and as surfaces of contact between the tube and fin during the subsequent soldering operation, to increase the thermal efiiciency at the joint region.

The tube 19, as shown in FIG. 11, has a locked seam 33 which is subsequently sealed by soldering.

My novel fixture will now be described, with particular reference to FIGS. 1 to 6.

In FIG. 1, the finished fixture is generally indicated by the numeral 1. It comprises an upper frame support 2, a lower frame support 3, and side plates 4 and 5, all held in proper relationship by bolts 6 passing through holes 7 in the side plates and through holes 8 in the upper and lower frame supports. Within the fixture are a series of spacer plate members 9, as shown in FIG. 4. The spacers are cut out as at 22 and 23 to provide a dovetail connection with the upper and lower support members which have a conforming shape, as shown at 20 and 21 in FIG. 2. Other arrangements for mounting the spacers 9 would be equally suitable, as the mounting arrangement has no important role in the utility of the fixture. The spacers 9 are in turn spaced on the supporting members by the spacing elements 10 and 11 illustrated in FIGS. and 6, respectively. Thus, between each pair of adjacent spacers 9 are a spacer element and a spacer element 11. The leading edge of the short spacer 10 is beveled as at 37 to perform a funnel function on the upper edges of the fins as they are inserted into the fixture.

The side plate members'4 and 5 and all of the spacer members 9 have corresponding cutouts 14, 15 and 16 through which access may be had to the openings 13 in the fins for insertion of the tubes. In FIG. 1, a tube 19 is illustrated in the partly inserted position and passing through the opening 16. The fins are inserted from the lefthand side for the reasons to be hereinafter described.

Spacers 9 have corrugations 34 to correspond with the corrugations 28 in the fins. However, the corrugations 34 are not uniform. They are narrow and shallow at the leading edge, and they become linearly wider and deeper as they approach the trailing edge in the vicinity of the tube insertion openings 14, 15 and 16. This feature of my invention has the dual function of providing a funneling action as the fins are inserted into the fixture to facilitate their entrance and to limit the critical spacing function of the spacers to the tube insertion region at openings 14, 15 and 16. The upper edge of slot 14 and the lower edge of slot 16 of the spacers 9 are cut, as at 35, and a portion of the edge is bent outwardly, as seen at 35 in FIG. 7, in the form of a saw-tooth. These points contact the fin in the region of the upper tab 32 adjacent the upper portion of the fin slots 13, while the corrugation 34 in the spacer contacts corrugation 28 of the fin immediately below the slot.

As illustrated in FIG. 7, the function of these projections 3435 in supporting the fin 12 is to provide a thrust bearing surface against which the fin is urged by insertion of the tube 19. These projections above and below the tube slot 13 minimize the amount of deformation to which the fins would otherwise be subjected, and assure uniform fin spacing in the finished product.

In operation, the width of the fixture is determined by the number of fins to be accommodated. For instance, in the automotive radiator field, where the tubes normally are vertically arranged, thefixture may be as much as two feet in-widthto accommodate many fins. The operation- J is illustrated in FIG. 1, where may be seen a series of fins 12 being inserted into the fixture. The fins must next be aligned at the trailing edge of the fixture so that the slots are all in alignment, with cut-outs 14, 15 and 16.

Where the tube 19 is insufficiently strong to withstand the pressure required to force it through a wide stack of fins, a mandrel (not shown) may be inserted irito the tube to prevent its distortion and then removed after the tube is inserted. After the first series of tubes have been inserted, the fins 12 are advanced until the next row of slots comes into alignment with the cutouts 14, 15 and 16, whereupon the next set of tubes are inserted. This is repeated until a unit of the desired Width is attained. It will be understood from FIG. 1 that each cut-out 15 is deeper than the cut-outs 14 and 16 by an amount equal to half the distance between the longitudinal center lines of two adjacent holes 13 in the fins 12.

I claim:

1. A device for assembling a plurality of radiator fins and tubes, each fin being in the form of a sheet having a substantially greater length than width and having two longitudinal edges and a row of perforations spaced lengthwise along the fin between said edges for receiving the'tubes, said device comprising the combination'of a plurality of separator plates interconnected in parallel, closely spaced relation to form interspaces in each of which one of sad fins is adapted to be disposed substan tially parallel to the plates, each interspace'being of a thickness at least as great as the maximum thickness of the corresponding fin, said plates being interconnected at opposed portions located, respectively, opposite the two longitudinal edges of the'respective fins when .the fins are so disposed in said interspaces, the plates having leading and trailing opposed edges extending generally transversely of said opposed portions and forming therebetween, respectively, entrance and exit openings to and from said interspaces, whereby the fins are adapted to move lengthwise through said interspaces from said entrance to said-exit openings while guided by the inter connected plates, the distance between said leading and trailing edges being substantially less than said fin length so that the fins are adapted to protrude lengthwise from the interspaces to provide exposed fin parts for effecting said lengthwise movement through the interspaces, said trailing edges of the plates having a plurality of aligned recesses adapted to receive one of said tubes at said exit openings and with which one perforation of each fin is adapted to be aligned by said lengthwise movement of the fins, said recesses opening in the direction of said lengthwise movement of the fins to allow continuance of said movement after insertion of a tube through the aligned recesses and fin perforations.

2. The combination defined in claim 1, wherein each of said separator plates has at least one corrugated embossment running from the leading edge to the trailing edge thereof.

3. The combination defined in claim 1, wherein each of said separator plates has at least one corrugated embossment running from the leading edge to the trailing edge thereof, said corrugated embossments gradually increasing in depth and width from the leading edge to the trailing edge of the corresponding separator plate.

4. The combination defined in claim 1, including also means for supporting said separator plates comprising blocks having'shaped projections thereon adapted to engage correspondingly shaped slots in said separator plates, and spacer members holding said blocks in spaced relationship.

5. The combination defined in claim 1, wherein the plane of the leading edges of said separator plates is out of parallel with the plane of the trailing edges of said plates.

6. The combination: defined in claim 1, comprising also thrust projections on the separator plates located adjacent said recesses to support the fins during insertion of a tube through said recesses and aligned perforations.

7. The combination defined in claim 1, comprising also thrust projections on the separator plates located adjacent said recesses to support the fins during insertion of a tube through said recesses and aligned perforations, said projections being formed by bent portions of the plates.

8. The combination defined in claim 1, comprising also means interconnecting said plates and including beveled edges for tunneling the fins into said interspaces.

9. The combination defined in claim 1, in which each said trailing edges of the plates have an additional plurality of aligned recesses for receiving an additional tube to be inserted through perforations in additional rows of perforations in the respective fins, said additional aligned recesses being deeper than the other aligned recesses.

10. The combination defined in claim 1, in which each of said recesses is adapted to receive the entire crosssection of one of said tubes.

References Cited in the file of this patent UNITED STATES PATENTS 1,802,929 Seelert Apr. 28, 1931 1,836,619 Ritter Dec. 15, 1931 1,979,856 Bennett Nov. 6, 1934 2,410,140 Young Oct. 29, 1946 2,664,842 Lornor Jan. 5, 1954 2,811,204 Kritzer Oct. 29, 1957 

